| | Shackle Island, TN | Smyrna, TN | United States |
| Population | 3,552 | 52,401 | 329,725,481 |
| Female Population | 50.5% | 50.6% | 50.5% |
| Male Population | 49.5% | 49.4% | 49.5% |
| Median Age | 44.9 | 34.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,736 | 40,589 | 309,327,143 |
| Population - 2000 | 2,106 | 25,569 | 285,036,114 |
| Population - 1990 | 1,447 | 13,647 | 251,960,433 |
| Pop. 2000 to Now | 42.6% | 108.0% | 15.6% |
| Pop. 1990 to Now | 107.5% | 289.7% | 30.8% |
| space4 | | | |
| Population Density | 640.8 | 1,729.0 | 93.4 |
| Land Area | 5.5 | 30.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.1 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Shackle Island, TN | Smyrna, TN | United States |
| Age 0 to 4 | 2.4% | 7.6% | 5.9% |
| Age 5 to 9 | 4.3% | 7.3% | 6.1% |
| Age 10 to 14 | 10.9% | 6.8% | 6.6% |
| Age 15 to 17 | 3.7% | 3.5% | 3.9% |
| Age 18 to 20 | 2.6% | 4.2% | 4.0% |
| Age 21 to 24 | 3.9% | 5.3% | 5.2% |
| Age 25 to 34 | 6.7% | 16.3% | 13.8% |
| Age 35 to 44 | 16.1% | 14.9% | 12.9% |
| Age 45 to 54 | 26.8% | 13.0% | 12.6% |
| Age 55 to 59 | 5.1% | 6.4% | 6.7% |
| Age 60 to 64 | 5.6% | 5.1% | 6.3% |
| Age 65 to 74 | 5.7% | 5.9% | 9.6% |
| Age 75 to 84 | 5.5% | 3.0% | 4.5% |
| Age 85 and over | 0.8% | 0.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Shackle Island, TN | Smyrna, TN | United States |
| White | 89.5% | 61.6% | 59.4% |
| Black | 6.2% | 17.0% | 12.2% |
| Asian | 0.0% | 5.0% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 0.6% | 3.6% | 3.2% |
| Hispanic | 3.6% | 12.3% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Shackle Island, TN | Smyrna, TN | United States |
| Married Population | 66.3% | 48.3% | 49.8% |
| Currently Married | 62.9% | 47.2% | 48.0% |
| Married but Separated | 3.5% | 1.1% | 1.8% |
| Single Population | 33.7% | 51.7% | 50.2% |
| Never Married | 20.9% | 34.2% | 33.8% |
| Divorced | 9.1% | 11.6% | 10.8% |
| Widowed | 3.7% | 5.9% | 5.6% |
| space5 | | | |
| Household Size | 2.82 | 2.74 | 2.60 |
| Households | 1,261 | 19,022 | 124,010,992 |
| Family Households | 1,071 | 13,173 | 80,755,759 |
| Married couple, w/children | 31.7% | 31.5% | 30.5% |
| Married couple, no children | 54.4% | 36.2% | 42.9% |
| Non Family Households | 190 | 5,849 | 43,255,233 |
| Single householder, w/children | 12.0% | 20.4% | 15.8% |
| Single householder, no children | 2.0% | 12.0% | 10.8% |